Effect of partial wrist denervation on wrist kinesthesia: wrist denervation does not impair proprioception

Surgical Feasibility Study on Cadaver for Vascularized Wrist Joint Transplantation

PURPOSE

Despite modern advancements in the treatment of late stages of wrist joint degeneration, few reliable options exist for patients requiring motion-preserving reconstruction of their radiocarpal and midcarpal joints. Vascularized composite allotransplantation (VCA) could be considered an option for wrist reconstruction in the future. The goal of this study was to describe the relevant anatomy and design a potential surgical technique for wrist VCA.

METHODS

Anatomic studies were performed on 17 human upper extremities. The arterial system of each cadaver was injected with latex dye or radiographic contrast. After injecting a contrast medium visible on a computerized tomography (CT) scan, the initial three specimens were examined using microCT. This confirmed joint vascular patency and allowed for the dissection of the other specimens that were injected with latex for the study of joint vascularization and the design of the wrist VCA. We then outlined a donor and recipient surgical technique for transplant based on recipient CT scans. Customized cutting guides were designed for the transplant procedure. After the procedure, we performed angiography of the VCA to determine the vascularity of the transplant.

RESULTS

Using a combined volar and dorsal approach, we were able to perform a complete wrist VCA procedure. After the completed transplant procedure, angiographic imaging of the specimens demonstrated that the flap dissection and transplantation preserved the nutrient endosteal supply to the distal end of the radius and ulna, as well as to the carpal bones and the metacarpal bases.

CONCLUSIONS

The dissection of the donor, recipient, and the entire vascularized joint transplant procedure served to illustrate the anatomical feasibility of the cadaveric surgical technique. This establishes an anatomic basis for the possibility of future human clinical applications.

CLINICAL RELEVANCE

This study helps investigate the anatomical feasibility of a wrist VCA.

Deep Peroneal Neurectomy for Midfoot Arthritis

Osteoarthrosis of the tarsometatarsal joint (TMTJ) and naviculocuneiform joint (NCJ) is a common pathology treated by foot and ankle specialists. Arthrodesis is the most widely accepted surgical treatment. Patients that are not candidates for arthrodesis are often left without surgical treatment options. Neurectomy has been described for treatment of upper extremity joint arthrosis but has not been well described in the foot. The deep peroneal nerve innervates the first, second, third TMTJs and NCJ. We present a retrospective case series on the outcomes of patients treated with deep peroneal neurectomy for TMTJ and NCJ arthrosis (N = 34 feet in 26 patients). The median postoperative American Orthopedic Foot and Ankle Society midfoot score was 53 (range 16-75) points. Twenty two (85%) of 26 patients stated that their expectations were met as a result of the deep peroneal neurectomy procedure, and 20 (77%) of 26 patients stated that they would have deep peroneal neurectomy for their symptoms again. There were recurrent symptoms prompting patients to seek additional treatment in 7 (21%) of 34 feet. Recurrent pain is also documented in hand denervation studies and the physiologic explanation remains unclear. Our results suggest that deep peroneal neurectomy is an effective treatment option for TMTJ and NCJ arthritis and may be particularly helpful in patients that are poor candidates for arthrodesis.

Posterior Interosseous Nerve Graft: Utilizing External Landmarks and Anthropometric Ratios to Predict Available Length for Digital Nerve Reconstruction in a Cadaveric Study

Objective:

In digital nerve defects that require grafting, autografts remain the efficacious option. The sensory posterior interosseous nerve (PIN) is an ideal choice as it is of similar caliber to digital nerves and leaves no donor morbidity upon resection. However, a finite length of harvestable PIN exists, and considerable variations of this length have been reported in the literature. There exists no predictive model to estimate this length. We sought to determine a method to accurately predict the available length of PIN based on individual patient anthropometry.

Methods:

A cadaveric dissection study was performed in a fresh tissue laboratory. The length of the sensory branch of the PIN and various anthropometric measurements were made in respect to surface anatomy of the ulna to develop a predictable ratio for available PIN donor graft.

Results:

A total of 16 specimens were obtained. On average the length of the PIN was 5.7 cm (range: 3.3-9. cm) and the length of the ulna was 25.7 cm (range: 23.5-30.6 cm). The ratio of PIN to ulnar length was 0.222 ( r = 0.4651). Using one-fifth the length of the ulna, the mean predicted length of the PIN was 5.14 cm (range: 4.7-6.1 cm). On univariate analysis, there was no significant difference between the measured and predicted PIN length ( P = .249).

Conclusion:

An anthropometric ratio predicated on reproducible surface anatomy of the ulna is a useful tool in predicting the sensory PIN length. Such a prediction may be a useful in guiding patient discussions concerning surgical options for digital nerve reconstruction.

Salvage procedure after malunited distal radius fractures and management of pain and stiffness

Indications for surgical treatment of distal radius fractures (DRF) remain controversial in the literature, especially in elderly patients. Complication rates after operatively treated DRF are low and well documented. These include malunion, degenerative osteoarthritis in the radiocarpal joint and subsequently pain and impaired hand function. If conservative treatment fails then salvage procedures are necessary. This review summarizes the therapeutic options available to treat degenerative osteoarthritis after malunited distal radius fractures, regardless of the initial operative or conservative treatment.

Evaluation of proprioception in denervated and healthy wrist joints

We recruited 25 patients after complete wrist denervation and 60 healthy adults to investigate conscious and unconscious proprioception of the wrist. Ipsi- and contralateral joint-position sense, force sense, and wrist reflexes were measured. The latter were triggered by a trapdoor, recording electromyographic signals from the extensor carpi radialis brevis, extensor carpi ulnaris, flexor carpi radialis, and flexor carpi ulnaris muscles. No significant differences were found for joint position sense, force sense, and wrist reflexes between both groups, except for reflex time of the flexor carpi ulnaris after denervation of the left wrist as compared with the left flexor carpi ulnaris in controls or in right operated wrists. At a mean follow-up of 32 months (range 8 to 133), we found no proprioceptive deficit of the conscious proprioceptive qualities of joint position sense, force sense, and the unconscious proprioceptive neuromuscular control of wrist reflex time for most muscles after complete wrist denervation. We conclude from this study that complete wrist denervation does not affect the proprioceptive senses of joint position, force sense, and reflex time of the wrist.

Finger joint denervation in hand osteoarthritis: Indications, surgical techniques and outcomes. A systematic review of published cases

In cases of osteoarthritis with preserved motion, joint denervation can be an effective alternative to arthroplasty or arthrodesis to reduce joint-related pain. Although denervation is a standardized procedure for wrist osteoarthritis, it is used sparingly for finger joints. We conducted a systematic review to summarize reported cases of finger joint denervation in hand osteoarthritis with a specific focus on surgical procedures and postoperative outcomes. PubMed, Cochrane and Science Direct databases were searched from 1998 to 2019 and 13 relevant articles were selected. Three hundred and twenty-five denervations were conducted on 291 patients. Distal interphalangeal (DIP) joint denervation was performed through a dorsal approach; 83% of patients were satisfied with the surgery and complications occurred in 58%. Proximal interphalangeal (PIP) joint denervation was performed through a palmar approach; 90% of patients were satisfied with the surgery; complications were observed in 14%. Good results were observed in 95% of patients who underwent metacarpophalangeal (MCP) joint denervation; complications were observed in 26%; denervation was carried out with dorsal and palmar approaches in all cases. Denervation of the trapeziometacarpal (TMC) joint was achieved through the Wagner approach (61%), multiple incisions (26%), or dorsal approach (13%); satisfaction rate was 91%, with a 6% complication rate. Finger joint denervation in hand osteoarthritis is a simple and effective procedure, providing satisfactory pain relief. Good results are reported in all studies, especially for PIP and TMC joint denervation. Further investigations should be conducted on DIP and MCP joint denervation.

An Anatomical Study to the Branching Pattern of the Posterior Interosseous Nerve on the Dorsal Side of the Hand

Partial denervation of the wrist can benefit patients with chronic wrist pain. A complication of partial denervation is loss of proprioception and hypesthesia on the dorsal side of the hand. Our aim is to evaluate whether the sensory branches of the posterior interosseous nerve could contribute to the loss of proprioception and sensation. The branching pattern of the posterior interosseous nerve was studied in 20 cadaveric hands. The terminal branches of the posterior interosseous nerve reached the metacarpophalangeal joints in three specimens (15%), the midshaft of the metacarpals in three specimens (15%), carpometacarpal joints in 11 specimens (55%), and the scapholunate joint in three specimens (15%). The finding that terminal branches of the posterior interosseous nerve can reach the metacarpals and the metacarpophalangeal joints indicates that the posterior nerve may contribute to the proprioception and sensation of the dorsal side of the hand. Clin. Anat., 33:678-682, 2020. © 2019 Wiley Periodicals, Inc.

Buying Time: Long-Term Results of Wrist Denervation and Time to Repeat Surgery

Background: This study reviews long-term outcomes of partial wrist denervation focusing on need for and time to revision procedure. Methods: A retrospective study was conducted of all patients undergoing partial wrist denervation between 1994 and 2014. At average latest follow-up of 6.75 years (range, 1-21 years), clinical and radiographic data and need for revision surgery were recorded. Results: There were 100 wrists in 89 patients (61 male, 28 female) with average age at surgery of 54 years (range, 26-80). Principal diagnoses were arthritis (58%), inflammatory (19%), and posttraumatic arthritis (7%). Average flexion-extension arc was 83% and grip strength 75% of unaffected extremity. Average Mayo Wrist Scores improved from 48 preoperatively to 77 postoperatively. Sixty-nine percent of patients did not undergo other procedures during the time interval studied. Thirty-one percent underwent revision at an average of 26 months following denervation (range, 2-165). Conclusions: Partial wrist denervation is a motion-preserving procedure for patients with refractory wrist pain with 69% in this series requiring no further procedures. The remaining 31% experienced average symptom relief for 2 years prior to ultimately undergoing revision operation.

Wrist Denervation: Techniques and Outcomes

Wrist denervation is a safe and effective procedure for the treatment of chronic wrist pain that can delay or eliminate the need for salvage or anatomically distorting procedure, such as proximal row carpectomy. The traditionally more extensive wrist denervation has evolved to procedures requiring fewer incisions. Efficacy of this procedure is corroborated by multiple publications either as a stand-alone procedure or as an adjunct to other procedures. This review provides an update on the status of wrist denervation.

Posterior Interosseous Neurectomy Alternative for Treating Chronic Wrist Pain

Background  Wrist denervation is one of the several available options for treating chronic wrist pain; partial wrist denervation performed through a single dorsal incision by resecting the distal posterior interosseous nerve provides good outcomes. Questions/Purposes  This study evaluated the results of posterior interosseous neurectomy (PIN) in patients with chronic wrist pain secondary to scaphoid nonunion advanced collapse (SNAC) and scapholunate advanced collapse (SLAC). Methods  In total, 30 wrists obtained from 28 patients (25 males, 3 females) were assessed. The dominant hands of 25 (right-handed) patients, nondominant hands of 5, and both hands of 2 were considered. The average age at the time of surgery was 35 (range: 19-50) years, and the average follow-up duration was 18 (range: 12-30) months. Fifteen and 13 patients had wrists with SNAC and SLAC, respectively, and all of those underwent PIN performed through the dorsal approach. The pre- and postoperative range of motion, grip strength, and pain relief percentage were recorded for all the 30 wrists. Results  The average postoperative Disabilities of the Arm, Shoulder and Hand score was 30 (range: 20-80), and the difference between the pre- and postoperative scores was statistically significant. Ninety percent of the patients were satisfied with the results of PIN and reported improvement in grip strength and pain relief. Conclusions  Thus, PIN may be an effective surgical technique for wrist reconstruction. Clinical Relevance  To help patients challenge pain and maintain their wrist joint range of motion.

[Treatment options for scaphoid nonunion advanced collapse]

Untreated scaphoid nonunion as a rule results in subsequent scaphoid nonunion advanced collapse (SNAC) wrist. While reconstructive treatment of the scaphoid in association with resection of the styloid process of the radius is still promising in stage I SNAC wrist, salvage procedures are available for higher degrees of SNAC wrist to reduce pain and to preserve the function of the wrist. Denervation, proximal row carpectomy and partial wrist fusion maintain wrist mobility. Total wrist arthrodesis and total wrist arthroplasty are salvage procedures in cases of panarthritis or failed motion-preserving procedures.

Phantom limb syndrome induced by combined spinal and epidural anesthesia in patients undergoing elective open gynecological surgery

BACKGROUND

During regional anesthesia, including combined spinal and epidural anesthesia (CSEA), patients may develop a perceptual alteration of limb position known as phantom limb syndrome (PLS). We aimed to identify factors that influence the PLS onset, to explore whether PLS predisposes to other postoperative symptoms, and to document the relationship between PLS and sensorimotor impairment during recovery.

METHODS

Psychological questionnaires for anxiety and depression were completed beforehand, then multimodal tests of sensory and motor function, especially tests of proprioception, were performed regularly afterward. Two hundred participants undergoing elective gynecological surgery under CSEA reported their experiences of PLS and other symptoms using Likert rating scales.

RESULTS

Prolonged preoperative fasting (odds ratio (OR) 2.34; 95% confidence intervals (CI) 1.21-4.52), and surgical history (OR 2.56; 95% CI 1.16-5.62) predisposed to PLS, but patients with more extensive anesthetic histories may be at lower risk (OR 0.57; 95% CI 0.31-1.08). Furthermore, significant correlations were observed between the recovery from PLS and the perception of joint movement within the deafferented area (R = 0.82, P < .01) and motor functions (R = 0.68). PLS increases the chance of experiencing postoperative fatigue, physical discomfort, and emotional upset.

CONCLUSION

This study is the first to have identified the risk factors for PLS, assessed the relationship between PLS and postoperative sensorimotor impairment, and its influence on postoperative complications.

The Effect of Triangular Fibrocartilage Complex Tear on Wrist Proprioception

PURPOSE

This study examined the influence of triangular fibrocartilage complex (TFCC) deep fiber tears on wrist proprioception.

METHODS

The study involved 48 subjects: 24 with deep fiber TFCC tears and 24 with healthy wrists. A specially created sensor measured wrist proprioception in 3 axes of movement. Absolute differences between target and subject-reproduced angles were compared in injured and healthy wrists and in injured and contralateral patient wrists. A greater difference in reproduced angles was deemed to reflect a lesser ability to approximate a target angle.

RESULTS

In wrists with TFCC injuries, 40° pronation and 60° pronation showed significantly greater differences between target and subject-reproduced angles compared with those in the control wrists. In wrists with TFCC injuries, 40° pronation demonstrated significantly greater differences between target and subject-reproduced angles than did those in patients' contralateral wrists. Proportions of outliers with absolute differences greater than 6° were significantly higher in 60° supination and 40° pronation in wrists with TFCC injuries.

CONCLUSIONS

Deep TFCC fiber detachment may lead to decreased wrist proprioception in 60° and 40° forearm rotation.

CLINICAL RELEVANCE

Deep TFCC fiber tear may contribute to decreased wrist rotational positioning sense and may have biomechanical importance in distal radioulnar joint stability.

Test–retest reliability of wrist joint position sense in healthy adults in a clinical setting

Introduction

Proprioceptive assessments of the wrist inform clinical decision making. In wrist rehabilitation, joint position sense has emerged as one way of assessing conscious proprioception with varying methods and minimal psychometric analysis reported. The purpose of this study was to standardise the wrist joint position sense test method for clinical use and to determine its test–retest reliability in a healthy population.

Methods

Four wrist positions (20° and 45° flexion, 20° and 45° extension) were measured twice in a random order, by a single rater, using a universal goniometer on the same day. The absolute error in degrees between each position and reposition was calculated. For relative reliability analysis, the intraclass correlation coefficient (3,1) was calculated. For absolute reliability the standard error of the measurement was calculated and Bland–Altman plots visually inspected.

Results

Fifty-five healthy volunteers (mean age 31.1 SD±10.25 years) were assessed. The mean absolute error, summarised for all positions for test and retest, was 3.98°. The intraclass correlation coefficients were poor to fair (0.07–0.47), and standard error of the measurement was 2° (rounded) for all positions. The limits of agreement were fairly narrow, and the Bland–Altman plots showed random distribution of errors for each position, therefore the measurement error was clinically acceptable.

Conclusions

The active wrist joint position sense test using goniometry demonstrated poor to fair test–retest reliability and acceptable measurement error in healthy volunteers. The wrist joint position sense angle of 20° flexion was the most reliable.

Partial Wrist Denervation: The Evidence Behind a Small Fix for Big Problems

Wrist denervation addresses symptomatic wrist pain without the morbidity and complication profile of more extensive surgical procedures aimed to correct the underlying pathology. The concept of wrist denervation is not new, but its practical application has been modified over the past 50 years. A variety of techniques have been described for various indications, with generally good results. In the United States, a simple, single incision partial denervation consisting of neurectomies of the anterior and posterior interosseous nerves is most commonly performed. Although data on this procedure are limited, most patients are satisfied with pain relief in the short term. There is no evidence that partial denervation procedures alter proprioception of the wrist, and this procedure shows promise as a good option for palliating pain without prolonged postoperative immobilization or leave from work. Preoperative injections do not seem to correlate well with postoperative results. Future studies are needed to assess the duration of relief and possible acceleration of underlying pathology.

Patient-rated long-term results after complete denervation of the wrist

The aim of this study was to examine the long-term results after the denervation of the wrist. Between 1977 and 2001, we treated 375 patients in our clinic. The mean age was 43.5 years; 81% were male and 19% female. The long-term results were assessed by a questionnaire assessing pain on a visual analog scale and patient satisfaction and by the DASH questionnaire. After a mean follow-up of 12.23 years, we found an overall pain reduction of 52.1%. In 67.7% of the patients, we found a relief of pain: of these, 44% are free of pain until today and 56% were temporarily asymptomatic. Patients with a painful osteoarthritic condition without dynamic instability and good range of motion are ideal candidates to benefit from the denervation. The complete denervation of the wrist is an effective treatment option in patients with painful wrist conditions to reduce pain and improve the overall function.

Denervation of the Wrist Joint for the Management of Chronic Pain

Wrist denervation for the management of chronic wrist pain is a safe and effective procedure that can delay or eliminate the need for more invasive and kinematically compromising salvage procedures. Wrist denervation has become increasingly popular since it was first described in 1959, and the technique has evolved from more extensive denervations to limited single-incision approaches. Many physicians have performed this procedure as a palliative approach to managing chronic wrist pain and as an adjunct to other procedures.

Wrist denervation of the posterior interosseous nerve through a volar approach: a new technique with anatomical considerations

PURPOSE

Full or selective wrist denervation is an effective treatment for chronic wrist pain. In this cadaveric study, a volar approach for prophylactic denervation of the posterior interosseous nerve (PIN) and the anterior interosseous nerve (AIN) was assessed, which can simultaneously be performed during volar approaches for distal radius fracture fixation or in combination with metalwork removal.

MATERIALS AND METHODS

In total 40 adult upper limbs, embalmed using Thiel's method, were investigated. Group 1 included 20 limbs of which the distances between AIN and PIN to the ulnar margin of radius were measured at levels 6, 8 and 10 cm proximal to the styloid process and the distance radial styloid process to proximal border of pronator quadratus which might be useful as an intraoperative landmark. Subsequently further additional 20 adult limbs (group 2) were used. Transection of the PIN via this volar approach at the evaluated best level of step 1 was performed and evaluated by dissection via a dorsal approach.

RESULTS

In group 1, the PIN runs within the interosseous membrane, from the ulnar border of the radius, 6.4 mm (SD 2.66) at 6 cm, 8.4 mm (SD 2.28) at 8 cm and 3.75 mm (SD 5.46) at 10 cm proximal to the radial styloid. The AIN runs within the interosseous membrane, from the ulna edge of the radius, 7.5 mm (SD 2.4) at 6 cm, 7.3 mm (SD 1.95) at 8 cm and 2.35 mm (3.42) at 10 cm proximal to the radial styloid. AIN and PIN were in close proximity at the 8-cm level which equals a 1-cm distance proximal to the pronator quadratus border. Group 2 showed a successful transection of the PIN through a single volar surgical approach in additional 18 out of 20 adult upper limbs.

CONCLUSIONS

This study shows the local anatomy of the PIN, allowing denervation via a volar approach.

Radical Wrist Denervation and Preliminary Results

Denervation is a well recognized procedure to treat degenerative or posttraumatic joint conditions, especially in cases where pain is a significant impediment to function even in the presence of stable and supple joint. However, this procedure currently is not as widely used for wrist surgeries as it merits. Denervation procedure obeys all-or-none phenomenon and we believe that even a few residual intact sensory fibers are able to transmit severe pain sensation and therefore every attempt should be made to target all the sensory supply to the wrist joint. In the present article a modified and radical technique using a single dorsal incision is proposed to address the hypothetical pitfalls of leaving undivided sensitive branches. Preliminary results of 21 cases operated on by this method are presented.

Multiplanar wrist joint proprioception: The effect of anesthetic blockade of the posterior interosseous nerve or skin envelope surrounding the joint

STUDY DESIGN

Randomized clinical trial.

PURPOSE

Contribution of the posterior interosseous nerve (PIN) and surrounding skin envelope to wrist proprioception is a topic of debate and the primary focus of this research.

METHODS

We performed a double-blinded, placebo control study in which subjects underwent baseline multiplanar testing of wrist proprioception. They were randomized to receive either anesthetic blockade of the PIN within the fourth dorsal compartment, or circumferential topical anesthetic blockade of skin surrounding the wrist. Corresponding opposite wrists underwent placebo intervention with saline injection or inert ultrasound gel. Subjects repeated proprioceptive testing.

RESULTS

Eighty subjects, 45 male and 35 female, mean age 33 years (range, 19-64 years), completed testing. The percentage of measurements falling outside a ±18° range did not differ between pre-treatment and post-treatment PIN blockade or for circumferential skin anesthesia.

CONCLUSIONS

Wrist proprioception appears to be a multifactorial phenomenon. Surgeons may sacrifice the PIN without concern for effect on joint proprioception.

LEVEL OF EVIDENCE

Level I.

Surgical Treatment of Upper Extremity Pain

If the patient with hand pain remains without significant relief and without recovery of function after appropriate pharmaceutical and physical modality treatments, it is appropriate to consider a surgical approach to the pain. Categories of pain amenable to a surgical approach are pain caused by nerve compression, pain caused by a neuroma, and joint pain of neural origin. Compressed nerve should be decompressed and depending on the intraoperative findings a neurolysis also should be performed. Painful neuroma must be resected to stop the pain generator. For a painful joint, the biomechanics of that joint must first be stable before denervation.

Salvage Operations for Wrist Ligament Injuries with Secondary Arthrosis

Wrist ligamentous injuries can be challenging to treat successfully. In some cases the ligament repair or reconstruction fails, resulting in instability and progressive degenerative changes. In other cases the original injury is missed, and the patient presents for the first time with established wrist arthritis. Multiple operations have been devised to treat patients with arthrosis secondary to wrist ligament injuries. This article discusses definitive salvage operations such as intercarpal arthrodeses and proximal row carpectomy, as well as other alternatives such as wrist denervation and radial styloidectomy.

Evaluation of Radiographic Instability of the Trapeziometacarpal Joint in Women With Carpal Tunnel Syndrome

PURPOSE

To determine whether median nerve dysfunction measured by electrophysiologic studies in carpal tunnel syndrome (CTS) is associated with thumb trapeziometacarpal (TMC) joint instability.

METHODS

We evaluated 71 women with CTS and 31 asymptomatic control women. Patients with generalized laxity or TMC joint osteoarthritis were excluded. We classified the electrophysiologic severity of CTS based on nerve conduction time and amplitude and assessed radiographic instability of the TMC joint based on TMC joint stress radiographs. We compared subluxation ratio between patients with CTS and controls and performed correlation analysis of the relationship between the electrophysiologic grade and subluxation ratio.

RESULTS

Thirty-one patients were categorized into the mild CTS subgroup and 41 into the severe CTS subgroup. There was no significant difference in subluxation ratio between the control group and CTS patients or between the control group and CTS subgroup patients. Furthermore, there was no significant correlation between electrophysiologic grade and subluxation ratio.

CONCLUSIONS

This study demonstrated that patients with CTS did not have greater radiographic TMC joint instability compared with controls, and suggests that TMC joint stability is not affected by impaired median nerve function. Further studies could investigate how to better evaluate proprioceptive function of TMC joint and whether other nerves have effects on TMC joint motor/proprioceptive function, to elucidate the relationship between neuromuscular control of the TMC joint, its stability, and its progression to osteoarthritis.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic II.

A comparative study on autologous bone grafting combined with or without posterior interosseous nerve neurectomy for scaphoid nonunion treatment

BACKGROUND AND AIM

Scaphoid nonunion (SN) is a challenging state after scaphoid fracture. The posterior interosseous nerve neurectomy (PINN) is often performed adjunctively with scaphoid reconstruction using autologous bone grafts. However, it remains unclear whether PINN has a prophylactic or therapeutic value, and thus it results superior to patients with SN without PINN.

METHODS

A retrospective study was performed to evaluate patients with SN who were treated with autologous bone grafts with (cohort 1) or without PINN (cohort 2) between 1996 and 2010. Clinical outcomes, Mayo-wrist score, quality of life by Short Form (SF)-36 questionnaire, and analysis of risk factors were included.

RESULTS

A total of 151 patients with SN met the inclusion criteria, and 48 were lost in follow-up. The mean follow-up was 71.3 ± 39.0 months. Out of the remaining 103 patients, the union rate was without a statistical difference (P = 0.847) between cohorts 1 and 2. Functional results and the Mayo score were comparable in patients with bone union between both cohorts (P > 0.05). The results of wrist-pain measurements, including visual pain scales and wrist tenderness, were found to be similar (P > 0.05). Additionally, there was no significant difference in the quality of life.

CONCLUSION

The comparative study on autologous bone grafts for scaphoid reconstruction revealed comparable results for both patients with and without PINN independent from the choice of bone graft. We anticipate a prophylactic value of PINN due to a potential injury or an irritation during dissection of the wrist capsule. Further research on PIN, its sensory characteristics, and its impact on wrist function is required.

Posterior interosseus nerve vs. medial cutaneous nerve of the forearm: differences in digital nerve reconstruction

Digital nerve defects are common in hand trauma and for primary or secondary nerve reconstruction, the autologous nerve graft remains the gold standard. This study compares the regeneration results and donor side morbidity of either the posterior interosseus nerve (PIN) graft or the medial antebrachial cutaneous nerve (MACN) graft. 16 patients (group A, age 43 ± 13 years) with digital nerve defects were treated with a PIN graft and 12 patients (group B, age 40 ± 15 years) received a MACN graft. The average nerve gap was 22 mm in each group. After a follow-up of 15 ± 8 months in group A, S4-sensibility were measured in 9 cases, S3+ in 5 cases and in 1 case S2 and S0. Up to an inconspicuously scar in projection of the fourth extensor-tendon compartment, there was no significant donor side morbidity. In group B, a S4-senibility has been obtained in 4 cases, S3+ in 5 cases, S3, S2 and S0 in each 1 case after a follow-up of 16 ± 11 months. Regarding the donor side morbidity, almost all patients complained about a disturbing scar formation and unpleasant paresthesia at the forearm down to the rascetta. Neuroma-associated pain has been detected in 4 cases. Although there has been no significant difference in terms of nerve regeneration, we recommend the use of the PIN graft for digital nerve reconstruction, since harvesting this nerve is fast and easy and without any donor side morbidity compared to the MACN graft.

Scapholunate instability: proprioception and neuromuscular control

From a kinetic point of view, the wrist is considered stable when it is capable of resisting load without suffering injury. Several prerequisites are necessary for the wrist to be kinetically stable: bone morphology, normal articulating surfaces, ligaments, the sensorimotor system, the muscles crossing the wrist, and all nerves connecting to ligaments and muscles. Failure of any one of these factors may result in carpal instability. The terms "scapholunate (SL) dissociation" and "SL instability" refer to one of the most frequent types of wrist instability, resulting from rupture or attenuation of the SL supporting ligaments. From a radiologic point of view, SL instability may be dynamic or static. Unlike static instabilities, which tend to be painful and dysfunctional, a good proportion of dynamic SL instabilities remain asymptomatic and stable for prolonged periods of time. Such a lack of symptoms suggests that a ligament rupture, in itself, is not enough for a joint to become unstable. Certainly, the process of achieving stability is multifactorial and involves normal joint surfaces, ligaments, muscles, and a complex network of neural connections linking all these elements. In this article, we will review the neuromuscular stabilization of the SL joint and the proprioceptive mechanisms that contribute to the dynamic carpal stabilization.